A formative evaluation of AnimalWatch

We present the results of a deep formative evaluation of AnimalWatch, an intelligent tutor for arithmetic. Students learned with AnimalWatch, and had a positive experience with it. Still, we detected AnimalWatch selected too easy problems. We proposed different hypotheses for this behavior and analyzed the performance of each ITS component, by observing the interactions of hundreds of students with the system. We conclude with a report of lessons learned that would make ITS better.